POTENTIAL MECHANISMS OF CLIMATE INFLUENCE ON SURVIVAL OF LARGE CALANUS ON THE EASTERN BERING SEA SHELF
Climate over the Bering Sea during this century underwent a major shift from cold to warm to cold conditions. The shift to warmer temperatures was accompanied by declines in abundance and biomass of large zooplankton which recovered to previous levels when cold conditions returned. Using a stage specific model of Calanus finmarchicus, driven with temperature, currents and food fields from a regional ocean circulation model with embedded ecosystem model, we are testing the hypothesis that these changes are related to the presence and duration of sea ice over the middle shelf domain during spring. Preliminary results suggest that Calanus in the southeastern middle shelf domain can reach maximum size by May – July during both warm and cold years. However, in warm years lacking cold bottom water over the southern middle shelf, respiration rates increase and lipid stores may be exhausted as early as November 1st. Thus, sea ice may influence Calanus survival by generating a cold bottom layer which provides a thermal refuge for individuals that undergo diapause, increasing the likelihood of survival through the following spring.
Coyle, K. O., University of Alaska, USA, email@example.com
Gibson, G. A., University of Alaska, USA, firstname.lastname@example.org
Pinchuk, A. I., University of Alaska, USA, email@example.com
Location: 316 B
Presentation is given by student: No